ASK THE DOCTOR

by Wesley W. Wilson, M.D.

NOTE: If you have any questions for "Ask the Doctor," please
send them to the Voice editorial office.  The only questions
Dr. Wilson will be able to answer are the ones used in this
column.
     Wesley Wilson, M.D. is an Internal Medicine
practicioner at the Western Montana Clinic in Missoula,
Montana.  Dr. Wilson was diagnosed with type 1 diabetes in
1956, during his second year of medical school.

     Q: I have been experiencing needle-like pains in my
feet and lower legs.  My doctor says he thinks the pain is
caused by diabetic neuropathy, and he knows of nothing I can
do about it.  Is he correct?  Is there any medication I can
use to help me deal with this pain?

     A: I'm sorry but I will have to answer your question
with a typical doctor's response that "it depends, more
evaluation is needed."
     Diabetic neuropathy is a frequent complication of
diabetes. Like most diabetic complications, it usually
occurs after years of diabetes and may manifest itself in
numerous different ways, such as: pins and needles
sensation, burning, or sharp shooting pains.  Sometimes,
neuropathy takes the form of lack of sensation, or a feeling
of numbness.  As the term suggests, neuropathy is pathology
or abnormality in nerve function. The symptoms a person may
have depends upon which nerves are affected, the degree of
abnormality in the nerve, and whether there are other
complicating problems.
     Probably the most frequent symptoms of diabetic
neuropathy are burning, tingling, or numbness in the toes
and feet.  These symptoms usually begin in the toes and
often progress to spread the abnormal sensation up the leg.
Occasionally, the patient may experience similar symptoms in
the fingers and hands.  It is felt that the longer the nerve
fiber, the more injury to nerve structure can occur.  As the
longest nerve fibers in the body stretch from the spinal
cord in the small of the back all the way to the toes, they
are the first to show abnormal function.  If the problem
progresses, shorter nerves are injured as well, causing
symptoms closer to the spinal cord, further up the legs, or
in the hands.
     Since the sensory nerves seem to be involved early, the
first symptoms noticed by the individual may be those of
abnormal sensation.  Lack of sensation in the toes and feet
(especially if coupled with impaired blood flow) is a major
problem increasing the risk of injury.  The person may
actually be unaware of minor injury to the feet, such as
ingrown toenails or wounds from tacks.  Then, because of
poor nutrition of the tissues related to decreased blood
flow, there may be diminished ability to fight infection.
Lack of warning and lack of defenses are as bad for an
individual as for an army.
     Any discussion of diabetic neuropathy must include the
warning that problems other than diabetes can cause abnormal
nerve function.  Exposure to some toxins, excessive use of
alcohol, poor diet, and especially a low B-12 level can
cause impaired nerve function which may resemble diabetic
nerve injury. That is the reason physicians often say "it
depends" when asked a question such as yours.  Usually,
careful examination, history evaluation, and testing can
help clarify the problem.
     It is very important to determine the cause of the
nerve abnormality, since nerve cells cannot be replaced if
they die.  Injury of the nerves is usually irreversible so
it is vitally important to discover the cause of nerve
injury or damage.
     The story of diabetic nerve injury and its treatment is
similar to that of other diabetic complications.  It is much
better to prevent them than it is to treat the complications
if they occur.  The Diabetes Control and Complication Trial,
"DCCT," showed that after only six and a half years the
group of diabetics treated with intensive control and
hemoglobin A1c averaging about 7% had half as much
neurologic abnormality as did the group treated with
"ordinary control" and  hemoglobin A1c of 9%.  It would seem
that any reduction in average blood sugar levels has a major
payoff with less nerve injury and less progression of nerve
injury if it is already present.
     Persons who have pancreatic transplantation and who are
able to achieve normal blood sugars at all times usually do
not have further progress of nerve abnormality.
     Tight control is difficult to achieve and does not
prevent all neuropathy.  There is active research to try and
determine other means to prevent progressive nerve injury in
persons with diabetes and other illnesses.  One such
technique consists of the administration of drugs called
Aldose reductase inhibitors.  Studies have shown less nerve
injiury and less nerve pathology after administration of
these agents to individuals with diabetes, and reduction in
neuropathy if they are taken early.  These agents are still
being tested, and are not yet approved by the Food and Drug
Administration for widespread use.
     What if you have diabetic neuropathy -- what to do?
First be very, very careful to take very good care of your
feet.  Check shoes for nails or rough spots, never go
barefoot, test bath water with yur elbow or a thermometer
before putting your feet in to prevent burns -- remember
your early warning systems are not working!
     Symptoms can be improved or reduced by using
medication, particularly tricyclic antidepressants, which
have been found to be very helpful in relieving the symptoms
of nerve injury even though they do not improve nerve
function.  They often are able to relieve the burning pain
and discomfort even though nerve function is still impaired.
     Application of capsain, an extract from the peppers
that fire up Tabasco sauce, can at times relieve the
discomfort of neuropathy, particularly if it is of a burning
type.

Conclusions:
    If you have diabetes mellitus, try to control it so as
  to avoid complications.
    If you do develop complications, try to control the
diabetes to slow their progression.
    If you develop neuropathy problems, talk them over with
  your physician and expect the physician to attempt to
  determine if the problems are caused by diabetes, or by some
  other complicating factor.  Also expect him to try to help
  give symptom relief and warnings.


